package com.serverapk.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Map;
import java.util.Set;

public class NexUtil {

    /**
     * 生成签名
     *
     * @param data 待签名数据
     * @param key  API密钥
     * @return 签名
     */
    public static String signature(final Map<String, Object> data, String key) throws Exception {
        Set<String> keySet = data.keySet();
        String[] keyArray = keySet.toArray(new String[keySet.size()]);
        Arrays.sort(keyArray);
        StringBuilder sb = new StringBuilder();
        for (String k : keyArray) {
            sb.append(k).append("=").append((String.valueOf(data.get(k))).trim()).append("&");
        }
        sb.append("key=").append(key);
        return MD5(sb.toString()).toUpperCase();
    }

    /**
     * @param data
     * @return String
     */
    public static String parseParamsToString(final Map<String, Object> data) {
        StringBuilder sb = new StringBuilder();
        Set<String> keySet = data.keySet();
        String[] keyArray = keySet.toArray(new String[keySet.size()]);
        for (String k : keyArray) {
            sb.append(k).append("=").append((String.valueOf(data.get(k))).trim()).append("&");
        }
        System.out.println("sendPara==================" + sb.toString());
        return sb.toString();
    }

    /**
     * 发送post请求
     * @param url Url地址
     * @param param post参数
     * @return string
     */
    public static String sendPost(String url, Map<String, Object> param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(NexUtil.parseParamsToString(param));
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }


    /**
     * 生成 MD5
     * @param data 待处理数据
     * @return MD5结果
     */
    private static String MD5(String data) throws Exception {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] array = md.digest(data.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (byte item : array) {
            sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
        }
        return sb.toString().toUpperCase();
    }

}
